Pyrexia of unknown origin (PUO) or fever of unknown origin (FUO) is frequently caused by common conditions that manifest atypically. There are various reasons that might cause fever, and they are categorised into infections, non-infectious inflammatory disorders, cancers, and other factors.
HIV-associated PUO, which includes patients who have HIV with fever as above for four weeks as outpatients or three days as inpatients, with an uncertain diagnosis after three days of investigation, where at least two days have been allowed for cultures to incubate.
For these reasons, it is important for physicians to approach PUO in a logical manner, and for the causes and approach to PUO to be continuously reviewed. In this article, we review the aetiology of PUO and the diagnostic strategies that may be used to investigate it.
The management of pyrexia of unknown origin (PUO) requires a systematic diagnostic approach followed by targeted therapy based on identified causes, with empiric treatment reserved for specific scenarios when the diagnosis remains elusive despite thorough investigation.
The term PUO was first defined in 1961 by Petersdorf and Beeson. According to their classical definition, PUO is a fever higher than 38.3°C (101°F) on several occasions, lasting more than three weeks, and without a diagnosis after one week of hospital evaluation.
Neutropenic PUO: Definition: A fever arising in individuals with a low neutrophil count (neutropenia), often associated with conditions like chemotherapy or bone marrow disorders.
Fever of Unknown Origin (PUO): Unravelling the Mystery Behind ... - Medanta
Learn about pyrexia of unknown origin (PUO), its possible causes, symptoms, and diagnostic approaches to identify underlying conditions and guide effective treatment.